Elsewhere in Lao Cai, temperatures tumbled to 12oC on average and 7oC in mountainous areas, said weather forecasters.

Locals felt a damp chill as light rain drizzled in the highlands together with thick fog and frost that lasted the entire day.

The provincial hydro-meteorological forecasting centre said another strong cold spell is likely to hit Lao Cai in a couple of days. It proposed that local administrations take measures to protect animals and winter crops.

Meanwhile, a low tropical depression is heading for the East Sea and is forecast to strengthen into a storm, the national Hydro-meteorological Forecasting Centre reported on December 11.

At 13.00 the depression was positioned about 380km north east of Truong Sa archipelago, with winds gusting between 39-49km/h.

In the next 24 hours, the depression is expected to travel south and southwest at a speed of 10km/h. In conjunction with the cold front moving toward the south, it will cause high tidal surges in the East Sea.